/*
 * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.struts2.dispatcher.ng.filter;

import java.io.IOException;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.StrutsStatics;
import org.apache.struts2.dispatcher.Dispatcher;
import org.apache.struts2.dispatcher.mapper.ActionMapping;
import org.apache.struts2.dispatcher.ng.ExecuteOperations;
import org.apache.struts2.dispatcher.ng.InitOperations;
import org.apache.struts2.dispatcher.ng.PrepareOperations;

import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;

/**
 * Handles both the preparation and execution phases of the Struts dispatching
 * process. This filter is better to use when you don't have another filter that
 * needs access to action context information, such as Sitemesh.
 */
public class StrutsPrepareAndExecuteFilter implements StrutsStatics, Filter {
	protected PrepareOperations prepare;
	protected ExecuteOperations execute;
	protected List<Pattern> excludedPatterns = null;
	/**
	 * Provide a logging instance.
	 */
	private static final Logger LOG = LoggerFactory.getLogger(Dispatcher.class);

	// FilterConfig 过滤器的配置，可以读取web.xml里面配置的一些参数
	public void init(FilterConfig filterConfig) throws ServletException {
		LOG.info("过滤器开始初始化");
		InitOperations init = new InitOperations();
		try {
			LOG.info("创建LoggerFactory");
			FilterHostConfig config = new FilterHostConfig(filterConfig);
			init.initLogging(config);
			Dispatcher dispatcher = init.initDispatcher(config);
			init.initStaticContentLoader(config, dispatcher);

			prepare = new PrepareOperations(filterConfig.getServletContext(),
					dispatcher);
			execute = new ExecuteOperations(filterConfig.getServletContext(),
					dispatcher);
			this.excludedPatterns = init.buildExcludedPatternsList(dispatcher);

			postInit(dispatcher, filterConfig);
		} finally {
			init.cleanup();
		}

	}

	/**
	 * Callback for post initialization
	 */
	protected void postInit(Dispatcher dispatcher, FilterConfig filterConfig) {
	}

	public void doFilter(ServletRequest req, ServletResponse res,
			FilterChain chain) throws IOException, ServletException {
		LOG.debug("\tdoFilter");
		HttpServletRequest request = (HttpServletRequest) req;
		HttpServletResponse response = (HttpServletResponse) res;
		Map<String, Object> requestMap = request.getParameterMap();
		Iterator<String> iter = requestMap.keySet().iterator();
		//打印请求参数
		while (iter.hasNext()) {
			String key = iter.next();
			LOG.debug("\t" + key + "\t" + requestMap.get(key).toString());

		}
		// 打印请求头
		Enumeration<String> requestHeadName = request.getHeaderNames();
		while (requestHeadName.hasMoreElements()) {
			String str = requestHeadName.nextElement();
			LOG.debug("\t" + str + "\t" + request.getHeader(str));
		}
		try {
			prepare.setEncodingAndLocale(request, response);
			prepare.createActionContext(request, response);
			prepare.assignDispatcherToThread();
			if (excludedPatterns != null
					&& prepare.isUrlExcluded(request, excludedPatterns)) {
				chain.doFilter(request, response);
			} else {
				request = prepare.wrapRequest(request);
				ActionMapping mapping = prepare.findActionMapping(request,
						response, true);
				if (mapping == null) {
					boolean handled = execute.executeStaticResourceRequest(
							request, response);
					if (!handled) {
						chain.doFilter(request, response);
					}
				} else {
					execute.executeAction(request, response, mapping);
				}
			}
		} finally {
			prepare.cleanupRequest(request);
		}
	}

	public void destroy() {
		prepare.cleanupDispatcher();
	}
}
